Ford 351w stutters/lurches/catches under load

My Ford 351w starts great, idles fine, revs up fine with no load, but as soon as I get it in the water and go to get on step, past 2000 rpm everything goes to hell with it stuttering/lurching/catching up for a fraction of a second/lurching etc.

This problem started after wintering, and then in the spring, I took it in to get a "tune up" which consisted of a distributor cap and rotor, and a $500 bill (Canada is insane). In the fall on the last run, we didn't have this stuttering problem.

1. I've taken the air filter off during operation, and I can't see any fuel coming out of the secondaries.

2. I've replaced the fuel pump (it works)

3. I've checked the plug wiring sequence to the distributor cap (it's correct)

4. I've cleaned the carb, checked the bowl-to-jet line, blew out all the jets in the secondaries, everything is really clean in there.

5. Checked the linkages when the engine isn't running, and the secondaries open up as they should.

6. The carb is fairly new, and I'm having a hard time believing it's some blockage in the carb because everything seems really clean.

7. The accelerator pump is operational and working fine.

8. I've replaced the water/fuel separator filter, no water in there.

9. There's a bit of corrosion on the exterior of the distributor, don't know if that's useful information.

Please help.

Thanks.

Are you sure this isn't a transmission slipping issue? Have you checked and/or topped off the fluid lately?

I guess when I said "revs up fine" in the original post that's misleading. I can still notice the hesitation when not under load, it's just far less pronounced.

There's no gap between the points, and the spring seems pretty strong..

Here's the gap just a tiny bit before the peak. Wouldn't it never fire if the points didn't break at the peak?

hayek wrote: 1. I've taken the air filter off during operation, .

Please post a picture. Hopefully you don't have an air filter. If so, it's potentionally a bomb you are driving.

hayek wrote: Presumably there is a spacer I can get to measure 0.018 in?

They are called feeler gauges.

Thanks. I'm in town now so I'll go buy some

Those points look pretty burnt to me. Maybe run some emory cloth thru them while you are in adjustment mode.

Also, make sure the centrifugal weights (under the points plate) are not rusted up &boyh have springs. 1 spring is supposed to be a little loose.

the "air filter"

Time to replace the points...

scootdogydog wrote: Time to replace the points...

The points were just replaced. Less than 1hr on the engine since they've been replaced.. but I can put new ones in there. The gap between the points at the widest is 0.017in., so a little closer than what they're supposed to be.

Fair enough, it's about time I learn to do that anyway. Thanks.

Ski Dim sells the springs, IIRC.

After your repairs, set the timing with a timing light, to be between 8-10 deg BTDC @ 600RPM.

It was a right of passage with us baby boomers to watch our dads or grandfather tune up the car in the fall. I also remember the stories of my dad watching his grandfather pour and scrape bearings. Someday my son will tell the story of him watching his dad checking the oil level by turning a knob on the driver information center